IEEE文献

duyonghappy

Abstract- The emphasis on higher data rates and spectral
efficiency has driven the industry towards linear modulation
techniques such as QPSK, 64 QAM, or multi-carrier
configurations. The result is a signal with a fluctuating envelope
which generates intermodulation distortion (IMD) from the
power amplifiers. Since most of the IM power appears as
interference in adjacent channels, it is important to use a highly
linear power amplifier. This paper describes the novel approach
of using a diode as an active linearizer in view of minimizing non
linear distortion introduced by the power amplifiers in wireless
communication circuits. In case of pHEMTs, this technique
reduces the effect of nonlinear terms generated by the voltage
variable input capacitance of the active device. A two stage
power amplifier using 0.5μm gate length GaAs pHEMT process
shows that the power amplifier is linear up to 5dBm of input
power after linearization, where as it becomes nonlinear at -
4dBm of input power before linearization.